Intake and relative palatability indices of acacia species fed to sheep and goats

An experiment was conducted to determine preference intake and relative palatability indices of Acacia karroo, Acacia nilotica, Acacia tortilis, Acacia sieberiana and Acacia rhemniana in sheep and goats using a completely randomized design. The size of Experimental Farm from which the browses were harvested was 1842.75 ha. The leaf samples were randomly collected from various young trees. The samples were analysed for proximate composition, measured for intake and relative palatability indices of sheep and goats. Dry matter (DM) content ranged from 917.4 to 936.8 g/kg DM and organic matter from 822.9 to 892.2 g/kg DM. All acacia species contained crude protein content (CP) of more than 7–17% required for grazing animals. The content of neutral detergent fibre (ADF) and acid detergent fibre ranged from 372.8 to 658.1 and 150.0 to 464.6 g/kg DM, respectively and were significantly (P < 0.05) different among the species. All of the acacia species had low levels (0–5.57 g/kg DM) of condensed tannins. The intakes of all feeds except A. karroo and A. rhemniana were high in both sheep and goats. The leaves from A. sieberiana had the highest palatability indice (Pi) while those of A. rhemniana had the lowest Pi in both sheep and goats. It was concluded that there was an effect of acacia species on intake and relative palatability indices. Species A. sieberiana, A. nilotica and A. tortilis have potential as livestock fodder, based on moderate to high CP value, low ADF, low tannins, high intake and relative palatability indices.     

Chemical composition,in vitro dry matter digestibility and in sacco degradability of selected browse species used as animal feeds under semi-arid conditions in Northern Ethiopia

The study was conducted in Abergelle district of Tigray, northern Ethiopia with the objectives of evaluating the chemical composition, in vitro dry matter digestibility (IVDMD) and in sacco degradability characteristics of foliages of major browse species. Samples of foliages from 12 and 10 browse species were collected during the wet and dry seasons, respectively. The samples of the browse species were collected based on their abundance in the district, preference by livestock to browse them, accessibility to browsing and their additional uses other than livestock feed. The neutral detergent fiber (NDF) was higher in the browse species during the wet compared to the dry season except for Sterculia africana and Ziziphus spina-christi. Similar trends were observed for acid detergent fiber (ADF) content except for Acacia asak. The condensed tannins content and the IVDMD of the browse species had inverse relationships in both seasons. The in sacco dry matter (DM) and nitrogen degradability parameters of the browse species were seasonally variable. Based on in sacco potential DM and nitrogen degradation of the browse species in both seasons, Acacia oerfota, Acacia tortilis, Balanites aegyptiaca, Boswellia papyrifera, Sterculia africana, Terminalia brownii and Ziziphus spina-christi were ranked to be superior in their nutritive value, and thus can have better use as animal feeds. Consequently, these browse species could be considered in agro-forestry systems for better integration of livestock production with available feed resources in semi-arid areas.     

对印度亚热带潮湿气候中的多种用途树叶作为草料的质量评价(英文)

多种用途树种和灌木在农业系统中有重要的作用,在减少饲料供求矛盾和补充世界各地饲料赤字,提高动物生产力方面有很大的潜力。同时,评价草料各种营养特性,利于生产定量平衡的饲料。评价12种多种用途树种(Acacia auri-culiformis,Albizzia procera,Dalbergia sissoo,Gliricidia macu-lata,Leucaena leucocephala,Samanea saman,Azadirachta in-dica,Eucalyptus hybrida,Gmelina arborea,Michelia champaca,Morus alba,和Tectona grandis)的树叶的营养特性,其中分别包括6种豆科和非豆科树种,指标包括:常规成分,细胞壁成分,总鞣质含量,大量(Ca和P)与微量元素(Fe,Cu,Zn,Mn和Co)含量,干物质体外消化率与有机物消化率以及代谢能量值。结果表明上述各参数都有明显的差异。有机物,粗蛋白质含量,石油醚提取物总量,粗纤维含量,无氮浸出物,总灰分的平均值分别为:(92.02±0.30)%,(16.00±0.74)%,(3.05±0.13)%,(18.97±1.07)%,(54.00±1.12)%和(7.98±0.30)%。豆科树种较非豆科树种有更高的粗蛋白质含量(18.30%和13.70%)。细胞壁成分中的中性洗涤纤维素,酸性洗涤纤维,半纤维,纤维素,酸性木质素含量平均值分别为:(52.48±1.05)%,(31.72±0.97)%,(20.76±0.88)%,(16.97±0.70)%和(9.57±0.62)%。总鞣质含量为(4.22±0.32)%。Ca与P之比合理,多种树种叶中Fe和Mn含量丰富,P,Cu,Zn和Co水平低于标准水平含量。干物质体外消化率与有机物消化率平均值分别为(48.96±1.30)%和(50.69±1.36)%。代谢能量值为(6.95±0.11)MJ·kg-1。粗蛋白质含量与干物质体外消化率与有机物消化率和代谢能量值成正相关;而这三个参数与中性洗涤纤维素,酸性洗涤纤维,和酸性木质素含量成负相关。结果表明:银合欢可作为优良饲料的树种,因为它具有最高的干物质体外消化率与有机物消化率以及代谢能量值(65.20%,67.66%和7.95MJ·kg-1),而Gliricidia maculata,Morus alba,Azadirachta indica,Dalbergia sissoo和Samanea saman可做较好类型饲料的树种,其它树种做饲料质量差。     

Nutrient intake,digestibility and rumen fermentation characteristics of sheep fed on selected forage sweet potato cultivars

Selected forage sweet potato cultivars (Ipomoea batatas Lam) have superior forage characteristics, have high rates of regeneration after harvest, are able to smother weeds and can tolerate diseases and moisture stress. However, little information is documented on their feeding value. The study objective was to determine nutrient intake, digestibility and rumen fermentation characteristics of sheep fed on four selected forage sweet potato cultivars (K158, Marooko, Mugande and Wagabolige). Cultivars did not influence intake of dry matter (DM) (93.8–98.1), organic matter (OM) (82.0–85.6), neutral detergent fibre (NDF) (37.6–38.8 g/kg W^0.75) and metabolizable energy (0.94–0.99 MJ/kg W^0.75); digestibility of DM (740.3–744.1) and OM (747.0–751.7 g/kg DM) and intake of digestible DM (69.8–72.6) and OM (61.3–64.4?g per kg W^0.75); rumen pH (6.80–6.86), molar percentages of acetate (68.34–69.59), propionate (21.35–22.58), butyrate (7.43–7.57) and acetate to propionate ratio (3.03–3.20). Cultivars influenced intake of crude protein (CP) (10.7–16.9) and acid detergent fibre (ADF) (25.9–28.5 g/kg W^0.75). Digestibility of CP (655.7–821.1), NDF (594.1–712.8) and ADF (477.0–483.7 g/kg DM); intake of digestible CP (7.0–13.9) and NDF (22.4–27.7?g per kg W^0.75) were also influenced by cultivar. CP and NDF digestibility differed among all four cultivars with Morooko and K158 having the highest CP and NDF digestibility, respectively. Sheep fed on K158 and Wagabolige ingested similar quantities of digestible CP (11.6–11.8?g per kg W^0.75), which was lower than in Marooko (13.9?g per kg W^0.75). The four cultivars provided superior feeds to sheep which classify them as high quality forages. Hence they have the potential to improve livestock production in Kenya.     

Nutritive value of botanical fractions of Moringa oleifera and Moringa stenopetala grown in the mid-Rift Valley of southern Ethiopia

Nutritive value of botanical fractions (leaves, twigs, pods and whole forage) of Moringa oleifera and Moringa stenopetala were evaluated based on chemical composition, in sacco dry matter (DM) degradability, in vitro gas production and in vitro organic matter digestibility. The objective was to characterize the nutritive value of the different morphological fractions in order to determine their potential as alternative sources of livestock feed. The crude protein content (g/kg DM) was highest (P < 0.05) in M. oleifera leaves (361.2) followed by M. stenopetala leaves (334.4) and lowest in M. oleifera twigs (79.1) and M. stenopetala pods (89.2). The fiber (NDF, ADF and ADL) contents were higher (P < 0.05) in the twigs and pods than the leaves and whole forage in both species. The different morphological fractions of both species had high mineral content, although the Na content was low or marginal in most fractions except whole forage and green pods of M. stenopetala. The in sacco DM degradability ranked the morphological fractions in the order of leaves > whole forage = pods > twigs after 24 h of incubation time. The potential degradability (A + B) was highest (P < 0.05) in M. oleifera twigs (97.9 %) and M. stenopetala leaves (98.5 %) and lowest in the pods of both species (64.4–69.5 %) with intermediate values in all other fractions. No significant differences were observed in the instantly fermentable fraction (a) and rate of gas production (c), whereas lower (P > 0.05) insoluble but slowly fermentable (b) and potential gas production (a + b) were recorded in the pods than in the other morphological fractions of both species. The study showed that the different morphological fractions of the two Moringa species are good source of nutrients with high degradability which could be used as potential supplements to low quality tropical roughages.     

Utilization of browse supplements with varying tannin levels by Ethiopian Menz sheep: 1. Intake, digestibility and live weight changes

The effect of tannins in browse supplements on intake, digestibility and live weight changes was evaluated using sixty-six male Ethiopian Menz sheep in a 90-day trial. Teff straw (Eragrostis tef) was fed ad libitum (control diet), or supplemented with 190 g dried leaves of six Sesbania sesban accessions with increasing levels of condensed tannin (S1, S2, S3, S4, S5 and S6), lablab (Dolichos lablab), tagasaste (Chamaecytisus palmensis), leucaena (Leucaena leucocephala) and goetzei (Sesbania goetzei), in a completely randomized block design. The condensed tannins were highest in goetzei, S6, S5 and leucaena, intermediate in S4, S3, S2 and S1, and lowest in tagasaste and lablab. The forages differed significantly (P < 0.05) in their rates of degradation and truly undegradable dry matter. Lablab had lower water solubility and higher (P < 0.05) truly undegradable dry matter than the other browse supplements. With increasing tannin levels among Sesbania accessions, there was a significant decrease (P < 0.05) in the rate of degradation. Animals supplemented with forage legumes with low condensed tannin levels such as lablab, S1, S2, and S3 had a lower teff straw intake than those on the control diet. The converse was true for those fed with the high tannin supplements such as S4, S5, S6 and goetzei. Supplementation significantly (P < 0.05) increased total dry matter intake and live weight gains (LWG). The animals on the control diet lost weight (–1.9 g/kgW^0.75, while the supplemented animals gained between 2.9 and 4.4 g/kgW^0.75 daily. Leucaena supplementation promoted higher (P < 0.05) LWG than lablab, S1 and goetzei. With increasing tannin levels among Sesbania accessions, there was an increase (S1 < S2 < S3 < S4) followed by a decrease (S6 > S5 > goetzei) in LWG. The digestibilities of total DM and the supplements did not differ significantly (P < 0.05) between the diets, although the neutral detergent fibre (NDF) digestibility decreased significantly (P < 0.05) with supplementation. The control diet had significantly higher NDF digestibility than the leucaena, S3, S4, S5 and S6 supplemented diets. Results have beneficial attributes at low levels in ruminants. Condensed tannins confer important advantages in ruminant nutrition with respect to the prevention of excessive degradation of protein in the rumen. This revised version was published online in June 2006 with corrections to the Cover Date.     

Intake,digestibility, nitrogen balance and certain rumen characteristics of Ethiopian Menz sheep fed teff straw supplemented with cotton seed cake,dry sesbania,dry leucaena or fresh leucaena

Twenty five rumen fistulated Ethiopian Menz sheep were used in a completely randomized block design to determine roughage utilization when different types of supplements (sesbania, leucaena, cotton seed cake (CSC)) and forms (fresh or dry leucaena) were fed. The chemical composition, intake, digestibility, nitrogen balance and rumen degradability coefficients were determined. Rumen pH and ammonia-nitrogen (NH₃-N) levels were estimated in samples taken at 1, 2, 3, and 6 h after feeding.There was substitution of teff straw dry matter by the supplements. Fresh leucaena effected the highest substitution. Supplementation enhanced (p<0.05) the dry matter degradation (DD) of teff straw at 6 and 12 hours of incubation but not (p>0.06) for the other incubation times. There were no significant differences (p>0.05) between treatments in the degradation constants: readily soluble component (a) slowly degradable fraction, (b) potential degradability (PD=a+b) and rate of degradation (C) and for rumen NH₃-N concentration, the ranking was CSC > sesbania > dry leucaena > fresh leucaena > teff straw alone (p<0.05). The particularly high substitution rate observed with fresh leucaena might suggest that bulkiness may be a limiting factor in the intake of low quality roughages supplemented with tree leaves. The lower DM and OM digestibilities of the supplemented diets were attributed to substrate preference by rumen cellulolytic bacteria. Excessively high levels of rumen NH₃–N (328 mg/l) in the CSC diet resulted in high urinary nitrogen losses (r ²=0.32;p<0.001) leading to low N balance. This may suggest that for the utilization of poor quality tropical roughages, moderate levels of rumen NH₃–N sustained over a longer period may be needed.     

Performance of Zebu Steers Grazing on Western Tanzania Native Forages Supplemented with <Emphasis Type="Italic">Leucaena Leucocephala</Emphasis> Leaf Meal

Information is lacking on the potential of leguminous fodder trees such as Leucaena leucocephala as a feed resource to supplement the native forages in traditional grazing management systems in the tropics. Two studies were conducted (1) to assess traditional fodder banks’ forage nutritive potential on animal production, and (2) to investigate the effect of Leucaena leucocephala leaf meal (LLM) supplementation on growth of steers grazing standing hay basal forages in the dry season. The traditional forages had low nutritive values indicated by low mean crude protein (CP) of 23 g kg⁻¹ dry matter (DM), and high fibre contents of 717, 546 and 153 g kg⁻¹ DM for neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL), respectively. The forages were poorly degraded in sacco and had low metabolisable energy (ME) (4.2–4.6 MJ kg⁻¹ DM). Mean washing losses A, slowly degradable DM fraction, B, potential degradability, (A+B) and mean 48 h DM degradability (DMD) of grazing land forages were 70, 471, 541 and 326 g kg⁻¹ DM, respectively. In the supplementation study, 16 growing steers (160.8±0.24 kg) were randomly allocated into four groups, in a completely randomized design. Four LLM treatment diets (T1, T2, T3 and T4), with four levels: 0, 0.4, 0.6 and 0.8 kg DM for control, low, medium and high LLM levels, respectively, were randomly allocated to the animals in the four groups for 70 days (d). LLM supplementation (p<0.05) improved mean weight gain from −0.30 to 0.26 kg steer⁻¹ d⁻¹, for T1 and T4, respectively. Steers on T4 gained (p<0.05) more weight compared to the animals in T1 and T2, though there was no (p>0.05) difference in weight gains between animals on T3 and T4 (0.14 vs. 0.26 kg steer⁻¹ d⁻¹, respectively). Standing hay basal forages alone could not sustain animal productivity during dry seasons unless corrected for protein. Higher levels of LLM supplementation prevented weight losses and improved the performance of grazing steers, a management practice thought appropriate to low income pastoralists in semiarid western Tanzania.     

Effect of pre-feeding forage treatments,harvesting stage,and animal type on preference of tagasaste (<Emphasis Type="Italic">Chamaecytisus palmensis</Emphasis>)

Tagasaste (Chamaecytisus palmensis), a multipurpose fodder tree, is highly productive in the tropical highlands. The forage has high crude protein (CP) concentrations but is reported to have low intake by ruminants. This study investigated the effects of plant harvest stage and feeding management (wilted, dried and fresh) on levels of tannins in tagasaste and on preference and intake by Menz sheep and cattle fed during the dry season. The treatments were (1) fresh tagasaste, (2) wilted tagasaste, (3) dried tagasaste and (4) native hay. There were three preference experiments using sheep (20.2 ± 0.66 kg) to investigate intake under ad libitum or restricted offering of the forages, and to assess effect of harvest age (6- or 10-month regrowth age) on ad libitum intake. In two further experiments ad libitum offerings of the forages were evaluated using young steers (131.2 ± 19.6 kg) and heifers (156.3 ± 5.4 kg). The CP (201 g/kg), hydrolysable tannin (150.2 g/kg) and condensed tannin (8.97abs measured as absorbance at 550 nm wavelength/g NDF) contents of tagasaste forage were not affected by the physical treatments and harvesting stage. When fed ad libitum, sheep preferred (P < 0.01) fresh forage to wilted or dry tagasaste (24.5 vs. 22.9 and 7.9 g dry matter (DM)/kg metabolic body weight (MBW). The restricted offering increased intake of the less preferred dried form. Regrowth age (6 vs. 10 months) did not affect sheep preference. Unlike sheep, steers and heifers preferred (P < 0.01) dried tagasaste rather than the fresh or wilted forage. Animal preference and intake were affected by the preparation method of the forage, but not by regrowth age. Methods to improve intake (for cattle), effects of long-term feeding and evaluation on the subsequent effect of anti-nutritional compounds during digestion and animal performance should be further investigated.     

Effect of diet inclusion of <Emphasis Type="Italic">Tithonia diversifolia</Emphasis> on feed intake,digestibility and nitrogen balance in tropical sheep

Feed intake and digestibility were evaluated in sheep fed low quality Taiwan grass supplemented with Tithonia diversifolia. Four wether hair sheep were housed in metabolic cages and fed with either Control concentrate 20%, Tithonia 20, 35 or 50% in a Latin Square design. Adaptation and, feces and urine collection periods were 14 and 7 days, respectively. Feed intake was increased (P < 0.01) from 58.5 in control to 86.1 g/kg^0.75 in sheep fed Tithonia. NDF intake and digestibility were affected by Tithonia level. Nitrogen intake increased linearly (P < 0.01) with increase in feces and urine excretion. N retention was similar (P > 0.1) among sheep fed Tithonia, but different (P < 0.05) from control. Inclusion of Tithonia foliage at 20% of the DM diet of hair sheep improved their intake of low quality Taiwan grass and nitrogen retention. Higher levels of Tithonia in the diet, however, increase nitrogen loss in feces and urine.     

Preference and Palatability of Indigenous and Exotic Acid Soil-tolerant Multipurpose Trees and Shrubs by West African Dwarf Sheep

Eleven acid soil-tolerant multipurpose trees and shrubs (MPTS) were assessed for preference and palatability with mature West African Dwarf (WAD) sheep using the cafeteria method. About 500 g each of the MPTS were weighed in triplicates into plastic feeding troughs and randomly placed around the perimeter of a Panicum maximum paddock (25 m × 25 m). Five ewes averaging 25.24 ± 0.69 kg were allowed 4 h access to the browse species daily for 12 d. Dry matter intake differed (p<0.05), ranging from 0.0 g in C. calothyrsus to 70.8 g in M. barterii. The number of animal visits, time spent and number of bites per visit on the browses also differed (p<0.05). There were positive correlations between DM intake and number of visits, number of bites, time spent on each fodder browsing and the coefficient of preference. The preference of the various MPTS by animals in descending order was M. barterii > A. cordifolia > L. leucoephala > B. monandra > D. guineensis > H. madagascariensis > T. tetraptera > T. africana > A. bella > B. grandiflora > C. calothyrsus.     

Effect of dried Gliricidia sepium leaf supplement on feed intake, digestibility and nitrogen retention in sheep fed dried KW4 elephant grass (Pennisetum purpureum) ad libitum

A feeding experiment was conducted to study the effects of supplementation with dried Gliricidia sepium leaves on dry matter (DM) intake, digestibility and nitrogen retention in sheep fed KW4 elephant grass. Four mature rams were fed elephant grass ad libitum supplemented with four levels of gliricidia leaves (0, 4, 8 and 12 g DM kg⁻¹ lwt day⁻¹) in a 4 × 4 Latin square design. Supplementation with gliricidia leaves decreased elephant grass DM intake (g DM day⁻¹ or g DM kg⁻¹ BW^0.75 day⁻¹). However, the effect of supplementation on total DM intake of the rations was not significant (P >; 0.05). Total crude protein intake significantly (P < 0.001) increased with increasing levels of gliricidia supplementation. Total DM digestibility and body weight changes were significantly (P < 0.05) improved by gliricidia supplementation; with the highest digestibility coefficient (60.5%) and body weight gain (89.3 g/day) obtained at 8 g DM kg⁻¹ lwt day⁻¹. Gliricidia supplementation significantly (P < 0.001) improved nitrogen intake, absorbed nitrogen and retained nitrogen but with no significant difference at 8 and 12 g DM kg⁻¹ lwt day⁻¹ level of supplementation. The highest efficiency of N retention by sheep (44.9%) was obtained at 8 g DM kg⁻¹ lwt day⁻¹ level of gliricidia supplementation. The results indicated that supplemention of KW4 elephant grass with small quantities of gliricidia leaves up to 8 g DM kg⁻¹ lwt day⁻¹ enhance utilisation efficiency of the total ration. Further increases in the level of gliricidia supplementation, under the conditions of this experiment, reduced the intake of elephant grass leading to substitution effects of the basal. This revised version was published online in August 2006 with corrections to the Cover Date.     

Utilization of browse supplements with varying tannin levels by Ethiopian Menz sheep: 2. Nitrogen metabolism

The effect of different condensed tannins concentrations on protein metabolism from browse supplements was investigated in a 90-day trial using sixty-six male Ethiopian Menz sheep. Teff straw (Eragrostis tef) was fed ad libitum (control diet), or supplemented with 190 g dried leaves of six Sesbania sesban accessions with increasing levels of condensed tannin (S1, S2, S3, S4, S5 and S6), lablab (Dolichos lablab), tagasaste (Chamaecytisus palmensis), leucaena (Leucaena leucocephala) and goetzei (Sesbania goetzei) in a completely randomized block design. The condensed tannins were highest in goetzei; S6, S5 and leucaena, intermediate in S4, S3, S2 and S1, and lowest in tagasaste and lablab. The supplemented animals had significantly (P < 0.05) higher total dry matter and nitrogen (N) intake than the ones fed teff straw alone. The digestibility of N was lower for the control diet than for any other treatment (P < 0.05). S1 and S2 supplemented diets had significantly higher (P < 0.05) N digestibilities than all other diets. Faecal N, urinary N and urinary N per kg N excreted were significantly different (P < 0.0001) between diets. With increasing tannin levels (among Sesbania accessions) there was a significant decrease (P < 0.05) in urinary N (S1 > S2 > S3 > S4 > S5), and an increase (P < 0.05) in faecal N (S1 < S2 < S3 < S4 < S5). Supplementation increased faecal N output significantly (P < 0.0001) as well as the N retention. Among the forage supplements, N retention was significantly (P < 0.0001) lower in lablab-, tagasaste-, leucaena-, S4- and goetzei-supplemented diets, than for S1, S2, S5 and S6. Apparent nitrogen digestibility was positively correlated (P < 0.001) with the supplement dry matter and crude protein (CP) degradation after 24 h (r = 0.93 and r = 0.85, respectively), the CP content (r = 0.87), and was negatively correlated with acid detergent fibre and neutral detergent fibre (r = –0.87 and –0.87, respectively). The CP degradability characteristics of the forages differed (P < 0.001) in water solubility (93–470 g kg^-1 CP), rate of degradation (2.58–9.73 %/h), lag phase (–1.36–13.37 h), and estimated escape protein (262–619 g kg^-1 CP). With increasing tannin levels (among Sesbania accessions), there was a significant decrease (P < 0.0001) in the rate of degradation (S1 > S2 > S3 > S4 > S5), and an increase in the estimated escape protein. The estimated rumen degradable protein (supplements) varied from 482 to 744 g kg^-1 CP, while intestine digestible protein and the undegradable protein varied from 140 to 314 g kg^-1 CP, hence the browses can supply adequate levels of rumen degradable and bypass protein. This revised version was published online in June 2006 with corrections to the Cover Date.     

Nutrient composition of mistletoe (<Emphasis Type="Italic">Viscum album</Emphasis>) and its nutritive value for ruminant animals

Mistletoe (Viscum album L. subsp. album) is known as an obligatory hemiparasite of trees and is consumed by herbivores in some places, especially during periods of forage shortage and drought. This experiment was conducted to determine nutrient composition and nutritive value of mistletoe with respect to vegetation stage. Mistletoe samples were collected from three different tree species [almond (Amygdalus communis L.), plum (Prunus domestica L.), and willow (Salix alba L.)] at three different vegetation stages (April, July, October) naturally growing in Central Turkey. Five samples were taken at each vegetation stage for each tree species. The samples were incubated in rumens of two 2-year old fistulated Holstein cows. Nutrient data and nutritive value indices were subjected to 2-way ANOVA using the GLM procedure. Crude protein and NDF concentrations and metabolisable energy level of the samples were in the ranges of 52.5–68.6, 291–330, and 7.8–8.4 MJ kg^?1 DM, respectively. There were also significant differences in DM, crude ash, Fe, Cu, and Zn levels among trees. As the vegetation progressed, there were linear decreases in DM, CP, and NDF and linear increases in ADF, Ca, Cu, and Zn levels. There were significant interaction effects for tree species by vegetation stage in terms of DM, ADF, and Zn. In vitro dry matter and organic matter digestibility coefficients were between 0.84 and 0.87 and between 0.52 and 0.55, respectively. It was also observed that degradation of V. album was almost completed after the first 48 h. The soluble and readily degraded portion of DM (fraction “a”) increased, whereas the insoluble but degradable portion of DM (fraction “b”) decreased with advancing vegetation stage. Effective degradability of dry matter (EDDM) also increased significantly as the vegetation progressed. Gas production from fraction “b” varied by tree species and the stage of vegetation. A significant interaction of tree species by vegetation effects on EDDM and gas production was also noted. After 48 h, cumulative gas production and fraction “b” ranged from 52.71 ml to 58.85 ml and from 48.8 ml to 75.4 ml, respectively. In general, the mistletoe was low in protein, moderate in fibre, and high in minerals. In conclusion, as long as a lack of deleterious effects on health and performance is shown in feeding trials, mistletoe has potential to be used as a dietary component in ruminant feeding.     

Litter dynamics and soil properties under different tree species in a semi-arid region of Rajasthan,India

Litterfall and decomposition are the two main processes accounting for soil enrichment in agroforestry. The extent of enrichment in soil properties depends on the tree species, management practices and the quantity and quality of litter. A field investigation was carried out to study litterfall production, decay rates, release of nutrients and consequent changes in soil physicochemical properties under crowns of four multipurpose tree species (MPTs) in irrigated conditions in farm fields. The species were Prosopis cineraria (L.), Dalbergia sissoo (Roxb.) ex DC, Acacia nilotica (L.) Del. and Acacia leucophloea (Roxb.) Willd. Annual accretion of litter ranged from 36 to 54 kg tree⁻¹ year⁻¹ and was highest under D. sissoo and lowest under A. nilotica. Total litterfall production was in the order: P. cineraria > A. leucophloea > A. nilotica > D. sissoo. P. cineraria showed the highest NPK concentration in litter. For all MPTs, a large pulse of litterfall coincided with the winter season (November to February). Litter of P. cineraria decomposed fastest while that of A. nilotica was slowest. More than 95% of the leaf litter of P. cineraria decomposed in 6 months, of D. sissoo in 7 months and A. leucophloea and A. nilotica in 9 months. Decomposition rate of litter was highly correlated with neutral detergent fibre (NDF) (r = −0.94) and P (r = −0.91) concentration. N, P and K release were best correlated with NDF, acid detergent fibre (ADF), P, lignin, lignin/N and C/P ratios and NDF alone explained 88% to 94% of the variability in litter decomposition and nutrient release rates. There was significant build up of soil organic carbon and available NPK in the agrisilvicultural systems but also a decrease in soil pH. Build up in soil fertility was significantly correlated with litterfall and soil improvement was greatest under P. cineraria.     

Palatability of multipurpose tree species: effect of species and length of study on intake and relative palatability by sheep

The potential forage value and appropriate length of study on intake and relative palatability ranking of 40 multipurpose tree species (MPTs) were determined using 24 sheep blocked on live weight and age. As the MPTs had different dry matter contents, intakes were also expressed as a ratio of quantity offered (A_i/D_i). Using daily Eragrostis tef straw offer (TD) and intake (T), relative palatability indices were calculated as R_i = (A_i/D_i)/(T_i/TD_i). There was a significant (P < 0.0001) decrease in correlation of intake measured in day 1 and subsequent days (r = 0.88, 0.81 and 0.79 for days 2–4, days 5–8 and days 9–12, respectively). A similar trend was observed on corresponding palatability indices. Individual animal preference and blocking did not affect intake and palatability indices significantly (P > 0.05), however significant (P < 0.0001) tree species differences were observed. Results on linear regression, correlation coefficients, palatability ranking and standard errors of means (adjusted palatability indices) indicate that, if palatability is done to predict long-term intake of MPTs, at least 5 days are appropriate in palatability assessment for sheep. Using mean palatability index (days 2–12), the MPTs were grouped into four clusters. The MPTs such as Leucaena leucocephala and Sesbania sesban which are known to have good nutritive value had high palatability. In the same classification group, there were less known species such as Acacia venosa, A. persiciflora, A. melanoxylon, A. hockii, A. polycantha, Tamarindus indica, Chamaecytisus palmensis, Tipuana tipu, Indigofera arrecta and Atriplex nummularia. Flemingia macrophylla, Erythrina abyssinica, Acacia salicina, Acacia coriacea, Albizia schimperiana, Ceratonia siliqua, Casuarina glauca and Erythrina burana had poor palatability. These species seem to have little forage value for animals with short-term adaptation periods. Gliricida sepium and Calliandra calothyrsus although currently being used by farmers had a medium palatability ranking.     

Biomass Production and Chemical Composition of Moringa oleifera under Different Management Regimes in Nicaragua

The effects of different planting densities (250,000, 500,000 and 750,000 plants ha⁻¹) and cutting frequencies (45, 60 and 75 days) on the biomass production and chemical composition of Moringa oleifera was studied in a completely randomised split plot design with four blocks, in Managua, Nicaragua, located geographically at 12°08′15′′ N and 86°09′36′′ E. The 75 day cutting frequency produced the highest fresh matter yield, 100.7 and 57.4 Mg ha⁻¹ year⁻¹, and dry matter (DM) yield, 24.7 and 10.4 Mg ha⁻¹ year⁻¹, during the first and second year, respectively. All planting densities produced the highest DM yield at 75 day cutting frequency. In the first year, the density of 750,000 plants ha⁻¹ produced the highest fresh matter yield, 88.0 Mg ha⁻¹ and highest DM yield, 18.9 Mg ha⁻¹, but in the second year the density of 500,000 plants ha⁻¹ gave the highest yields, 46.2 Mg ha⁻¹ and 8.1 Mg ha⁻¹, respectively. During the first year, DM (22.8%), neutral detergent fibre (NDF) (30.8%) and ash (9.14%) contents were highest and in vitro DM digestibility (IVDMD) (68.2%) was lowest in the longest cutting interval, while contents of crude protein (CP) (22.8%) and acid detergent fibre (ADF) (22.8%) were not affected significantly by cutting frequency. In the second year, DM and CP contents and IVDMD were not significantly affected by cutting frequency, whereas NDF, ADF and ash contents were lowest in the 60 day cutting frequency. Planting density had no significant effect on chemical composition or IVDMD. These data suggest that Moringa forage could be an interesting protein supplement for ruminants.     

Ruminal in situ disappearance kinetics of six nutritive ingredients in leaves and stems of young tetraploid black locust in growing steers

Tetraploid black locust (Robinia pseudoacacia) is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant forage. However, currently no stockbreeders have adopted it as a major forage in China and other countries for a lack of information on the evaluation of nutritional ingredients of leaves and stems of young tetraploid black locust (YTBL) by in situ digesting tests. The objectives of this study were: 1) to assess the nutritive value of YTBL that bourgeoned from root stumps in the spring by determining the ruminal in situ disappearance kinetics of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF) and acid detergent fiber (ADF) from leaves, stems and a mixture of both leaves and stems (MLS) of YTBL; 2) to compare these kinetic estimates with those of Leymus chinensis, a widely used ruminant forage in China. All samples were evaluated in situ by using five ruminally cannulated crossbred steers (550±22.7 kg BW). The results of 48 hours, the representative incubation period, indicate that in situ disappearance rates of DM and OM in YTBL leaves, stems and MLS are on average about 40% and can attain the level of digestibility of L. chinensis. In situ disappearance rates of leaves, stems and MLS of YTBL for CP and EE were 41% and 58% respectively, rates higher than those of L. chinensis. But the disappearance rates of NDF and ADF were, on average, respectively 30.62% and 24.89% and lower than those of L. chinensis. By analyzing synthetically all of our results it could be inferred that MLS of YTBL offers effective ruminal degradability of DM, NDF, ADF, CP, EE and OM, similar to the nutrients of L. chinensis. This supports our contention that the YTBL leaves, stems and MLS are suitable feed for those ruminants requiring high levels of nutrients, such as dairy cows and Boer goats, instead of plant forage, which is decidedly lacking in some parts of the world.     

Gliricidia sepium as an alternative protein supplement to cottonseed cake for smallholder dairy cows fed on Napier grass in Tanzania

Lack of availability, poor quality forages and cost of concentrate feeds, especially during the dry season, are some of the major problems faced by smallholder dairy producers in the tropics. Therefore, two experiments were conducted to evaluate the nutritive value and economic benefits of substituting cottonseed cake (CSC) by Gliricidia sepium (GS) for milk yield and composition of crossbred dairy cattle. In experiment one chemical composition of the two feeds and their dry matter degradability (DMD) were determined. GS had (P < 0.05) higher dry matter degradability (DMD) than CSC. Potential DM degradability (PDMD) and degradation rate constants (c) of CSC and GS did not vary (P > 0.05). In experiment two, four treatment diets, all based on Napier grass, maize bran, mineral/vitamin mixture and two levels each of GS and CSC, were fed to milk cows in a 4 × 4 Latin square experiment. The treatments were, T1 = 0 GS + CSC 18%, T2 = 18% GS + CSC, T3 = 23.4% GS + CSC and T4 = 39.7% GS + CSC. Cows on T1 and T3 showed (P < 0.05) higher total DMI, metabolizable energy intake (MEI) and milk yield than cows on T2 and T4. There were no differences (P > 0.05) in milk protein, butterfat and total solids contents between the treatments. Cost analyses showed diet T3 to be more profitable than the other treatments, suggesting that the use of GS in combination with CSC is more profitable than when either of the two was used alone.This revised version was published online in November 2005 with corrections to the Cover Date.     

Shrub yield and fodder quality variations in a non-tropical dryland environment in West Asia

Integration of shrubs into the smallholder crop-rangeland-livestock farming systems in non-tropical dry areas could reduce feed gaps, rangeland degradation and desertification, but data on yield and fodder quality of most native and exotic shrubs are scanty. The study aimed at identifying shrubs for dryland agroforestry based on agronomic and fodder quality attributes. Fodder and wood yield, percent fodder (FBR) and fodder quality of 26 non-legume shrubs were determined from 6 to 8 months regrowth in north-west Syria. Seed yield was estimated from plants that were not cut. Fodder (31–87 Mg DM ha⁻¹), wood (16-2064 Mg DM ha⁻¹) and seed (0-132 Mg DM ha⁻¹) yield, FBR (24–87%), fodder concentrations of crude protein (69–195 g kg⁻¹.), acid detergent lignin (ADL) (24–109 g kg⁻¹), acid detergent fiber (ADF) (102–267 g kg⁻¹), neutral detergent fiber (NDF) (214–526 g kg⁻¹), in vitro organic matter digestibility (IVOMD) (391–526 g kg⁻¹), and in vitro gas production after 24 h of incubation (25–39 ml 200 mg⁻¹ DM) varied (P < 0.05) among the shrubs. Atriplex halimus-halimus and A. herba-alba from Spain, A. canescens, A. ploycarpa and A. lentiformis from USA, A. halimus and A. herba-alba from Syria and A. nummularia from Australia and South Africa had greater potential for development of dryland agroforestry technologies. The promising shrubs could be integrated into the rangeland-crop-livestock systems in non-tropical dryland environs to provide fodder, fuel-wood, shade, medicine, stabilize sand-dunes, and sequester carbon; thereby contributing to mitigation of rangeland degradation and global warming; if major constraints to adoption of fodder trees such as agronomic problems, low multipurpose value, land shortage and quality seed supply could be overcome.